Automatic switch



Aug. 11, 1931. E BESAG 1,818,682

AUTOMATIC SWITCH I Filed Feb. '7, 1928 Patented Aug. 11, 1931 PATENT OFFICE ERNST BESAG, OF BADEN-BADEN, GERMANY AUTOMATIC SWITCH Application filed February 7, 1928, Serial No. 252,641, and in Germany February 2, 1927.

The invention relates to an improvement in the automatic switch described in the application, Serial Number 7 27,063 of July 19, 1924. In this switch the supports of the stationary contact elements, in the form of bare rigid conductors without the use of insulators submerged in oil, extend directly from the circuit terminals on the upper part of the switch to the stationary contact elements on the low 19 er part of the switch, and the rigid conductors between the circuit terminals and the stationary contact elements are used for housing all the release elements. All the input conductors serving for the various phases and likewise the corresponding output conductors are carried by a common carrying strip which consists of insulated material which is arranged vertically in the housing. Between the ingoing conductors and the outgoing conductors there is provided a cross bar which carries the movable contact elements and is controlled in its releasing movement by a locking mechanism made of plates arranged side by side so that the whole locking mechanism is substantially flat.

In accordance with the present invention all the parts of the switch are fastened upon the checks of the lock or locking and actuating mechanism, between which the movable lock elements are arranged. In this way the dimensions of the switch become materially smaller, which obviously is of considerable importance.

The figures show, by way of example, two embodiments of the invention, namely, an air switch and an oil switch.

Fig. l is an elevation Fig. 2 a side view, and

Fig. 3 a plan of the air switch.

Fig. 4- is a side view of the oil switch.

Figs. 2 and 4 show the switch elements with the release mechanism removed from its housing within the walls of the channelshaped member forming part of the rigid input conductor. The release mechanism which has been removed comprises the bi-metallic strip and its associated undulated spring, etc. i

Fig. 5 shows the rigid input conductor or ingoing side of one phase, inclusive of the re T lease mechanism for this phase, in elevation.

may be a toggle system, parts of which may Fig. 6 is a side viewcorresponding to Fig. 5.

Figure 7 is a fragmentary perspective view of the bimetallic strip mounted in the channel member.

Upon the base plate 1 which may consist of cast iron are securedthe lock plates 2 between which are arranged the movable parts of the lock or locking and actuating mechanism. The locking and actuating mechanism may be formed in any desired way, preferably in accordance with my application, Ser. No. 256,656 of February 24, 1928. The actuating and locking mechanism is indicated by the reference character and in the embodiment of the invention which is illustrated it 6 be seen in Figs/1, Q, 3 and a. The lock is made up of a plurality of flat plates forming the toggle system all positioned between the two spaced plates 2, 2 which are fastened to the base plate 1 and serves 2. supports or frame for the lock mechanism. The elements of the toggle system are not only positionedbetween the plates 2, 2 but are supported therefrom, and, in turn, support a cross bar 4 upon which the movable contact elements 5, 5 of the switch are mounted. By moving the handle 3 the cross bar 4 is lifted or depressed so that the movable contact ele ments 5 secured thereto may be pressed against the opposed stationary contact elements or removed therefrom. The stationary contact elements are carried by the bare rigid conductors, which extend directly from the circuit terminals 7 at the upper part of the switch to the stationary contact elements in the lower part of the switch. These rigid bar conductors form input and output conductors for the switch and are supported upon the outside of the plates 2 by means of insulating plates 6. The insulating plates are "two in number, one supporting all the input conductors and the other all the output conductors.

The rigid input conductor on the left or 9 input side Fig. 3 is made up of two main. parts, as wn cearly in 2, 5 6. The upper of each input conductor comprises a term nal plate '7 and a prolongation thereof which extends into a channel shaped member having side walls designated by the reference numeral 22. The prolonged portion of the terminal plate overlaps the upper portion of the channel shaped member but is insulated therefrom for a reason to be described hereinafter.

A U-shaped, bent bimetallic spring 9 which slit partly down the middle so as to form two fork ends, is connected by one free end to the extension of terminal plate 7 and by the other free end to the channel member 22, 22. This connection may conveniently be made in the manner illustrated best in the perspective view of Fig. 7. Between the terminal plate 7 and the channel member 8 is placed an insulating block 26. Another insulating block 27 is placed upon the bimetallic strip 9. The right leg of the bimetallic strip is in contact with terminal plate 7. The left leg of the bimetallic strip is insulated from terminal plate 7 by a strip of paper 28 the other end of which is held between the channel member 8 and the insulating block in front of it. A metallic strap 29 lies upon the paper strip 28 so as to form a conductive connection from the left leg of the bimetallic strip 9 to the channel member 8. In this way, and because the terminal plate is insulated from the channel member. a path for current is provided which extends from the input binding post and terminal plate 7 to one forked end of the bimetallic sprin through the bimetallic spring and out the other forked end to the channel member 22. 22. The complete circuit for the switch thus is as follows: The ingoing binding posts and terminal plate 7, the bi-metallic springs 9, the channel member 22. the stationary contact elements, movable contact elements 5, rigid conductors and outgoing binding posts 7. The rigid output conductor upon which the outgoing binding post 7 is mounted need not be channel shaped but may comprise a flat plate extending from the output binding post at the top to the stationary contact at the bottom, as shown in Fig. 1.

In the free space 8, provided between the walls 22 of the channel member is provided a leaf spring 10 acting as a power storing means, which is kept in an undulated shape by the adjustable stop 12 and by the members 11, whereby it is held in substantially unstable equilibrium. The cross bar 13 of insulating material which is pivotally secured to the elements 22 extends along all the poles of the switch and carries a striking pin opposite each undulated spring 10. Inasmuch as the springs 10 are in substantially unstable equilibrium, they are transferred by even a slight expansive motion due to heat of the overload release by bimetallic springs 9, into the position shown in dotted lines, whereby a part of the potential energy stored therein is released and produces a rotation of the insulated cross bar 13. Upon this rotation or turning the finger 14 strikes against the releasing member of the locking and actuating mechanism, which is thereby released, so that the movable contact elements 5 an be moved under the influence of the disconnectihg power of springs or weights away tom the opposing stationary contact elements. The switch is then automatically switched off. The measuring instrument 19 which is secured to the plate 2 serves for controlling the current, strengths.

The oil switch in accordance with Fig. 1 is constructed essentially in the same manner as the above described air switch. It differs from the latter however in the manner of securing or mounting the plates 2. The plates 2 of the lock are supported on one side by the drive shaft or rod 16 of the locking and actuating mechanism which passes through them and which is supported in the housing 20 of the oil switch, and on the other side these plates 2 are fastened on a shoulder 18 of the housing 20 of the oil switch by means of the screw 17. The housing 20 of the oil switch has a window 21, back of which is located the measuring device 19 secured to the spaced plates 2, 2. It is therefore possible to make measurements even when the cover of the housing 20 is left off, which was not possible in previously known switches, wherein the measuring device was fastened in the cover of the housing. In these switches the fastening of the measuring device in the cover of the housing was never sulliciently tight, so that through the small cracks present, vapors and gases always entered into the interior of the housing. This disadvantage is eliminated by the invention.

The method of Operation of the new switch is precisely the same as that of known automatic switches. By operation of the handle 3 the locking and actuating mechanism is put in motion, so that the movable contact elements 5 engage the stationary contacts. The above stated current path of the switch is then closed. Through further actuation of the handle 3 in opposite direction the circuit may then be again manually opened. If, with the switch closed, a current of excessive strength occurs in one phase only, an automatic release'takes place. This is initiated by the motion of one or more of the bi-metallic springs 9, according to whether only one or more phases are overloaded. The bimetallic springs 9 pressing against the undulated springs 10, displace the latter into their dotted line bulged position, whereby the insulating cross bar 13 is oscillated in the direction of the arrow, so that its finger 14 shifts the releasing member 15 of the lock. The lock of the switch is opened by the shifting of the releasing member 15 so that the disconnecting powers of the switch may become active. The insulating cross piece 13 in moving back again loads the springs 10. It will be observed, particularly from exam,- ination of Fig. 5, that the automatic release means constituted by the bi-metallic strips and the undulated springs with their associated stops, abutments, etc., are housed entirely within the walls of the channel shaped members 22, 22. These channel members are supported by insulating sheets 6 upon the outsides of the plates 2,2. The common cross bar 13 which carries the striking pins for all release mechanisms is pivotally mounted on the channel members 22, 22 and is thus supported from, the cheek plates 2, 2. The stationary contacts are supported at the ends of the rigid input and output conductors which are mounted on the outside of the plates 2, 2. The movable contact elements 5, 5 are mounted on the lower end of the member 4 which forms part of the lock mechanism, and are thus supported between and from the plates 2, 2. The result is a very compact and efficient arrangement all the structural parts of which are supported from the plates 2, 2 of the locking and actuating mechanism and the width of which, no matter how many pairs of rigid conductors are used, is no greater than the width of the lock plus the width of a pair of the rigid conductors one on each side of the spaced plates 2, 2. This compactness is also due to the housing of the release mechanism comprising bimetallic strips and undulated springs within the Walls of the channel-shaped rigid, input conductors.

I claim 1. ,An automatic switch comprising a pluing the operating shaft of said locking mechanism, said spaced plates being supported at one end upon said rod, and means for fastening the other ends of said spaced plates to said housing.

4. An automatic switch comprising a pair of spaced plates, a locking mechanism, movable contacts mounted on a cross bar and a supporting rod therefor, the parts of said locking mechanism and the supportingrod being arranged between said spaced plates, and additional structural parts mounted on said spaced plates comprising stationary contacts, connecting terminals, release mechanism, and mechanical means for transferring movement from the release mechanism to the locking mechanism;

5. An automatic switch comprising connecting terminals, movable and stationary contacts, a flat locking mechanism, a supporting rod for said'movable contacts, a supporting plate for said locking mechanism, pieces of insulating material between which said locking mechanism, rod and supporting plate are arranged, means securing said insulating material directly to said supporting plate, a release device, structural parts for transferring movement of the release device to the lockingunechanism, and means for mounting said connecting terminals, stationary contacts, release device and said structural parts upon said insulating material.

In testimony whereof I aflix my signature.

' ERNST BESAG.

rality of constructional parts forming connecting elements and switch elements, a looking mechanism, a pair of spaced plates be tween which the elements of the locking mechanism are mounted, and means for mounting all of said constructional parts upon said spaced plates.

2. An automatic switch comprising a plurality of stationary constructional parts forming connecting elements and switch elements, a locking mechanism, a pair of spaced plates between which the elements of the locking mechanism are mounted, movable switch contacts supported by the interposition of parts of the locking mechanism from said spaced plates, insulating sheets secured to the outer sides of said spaced plates and means for supporting all of said stationary constructional parts thereon.

3. An automatic switch comprising a plurality of, constructional parts forming connecting elements and switch elements, a locking mechanism, a pair of spaced plates between which the elements of the locking mechanism are mounted, means for supporting all of said constructional parts upon said spaced plates, a housing adapted to contain oil, a rod mounted in said housingand form- 

